Chino Hills, CA Accessory Structures: Garage Conversions (2026)

Converting a garage into living space in Chino Hills is handled through the city's accessory dwelling unit process under Section 16.10.140 of the Development Code, which implements California ADU law. A 'conversion' ADU is created by converting all or part of an existing structure such as a garage, and a JADU (up to 500 square feet) may be created within the single-family residence or its attached garage. Consistent with state law, when an existing garage is converted into an ADU, the off-street parking spaces lost in that conversion are not required to be replaced - a significant benefit that removes a common obstacle to garage conversions. The converted unit must still provide complete independent living facilities (a living area, a sleeping area, a full kitchen with stove, refrigerator and sink, and a bathroom), and a JADU must include at least an efficiency kitchen with a cooking appliance, sink, and food-preparation counter/storage, with exterior access independent of the main home. A building permit is required, and conversions that meet the chapter's objective standards are approved ministerially. Importantly, a garage converted to habitable space that is NOT permitted as an ADU or JADU - for example an unpermitted bedroom or room addition - is treated as an illegal conversion subject to code enforcement.